Colorado History

The United States acquired part of the area that is now Colorado from France as part of the Louisiana Purchase in 1803; part from territory ceded by Mexico in 1848, and part from territory sold to the United States by the state of Texas in 1850. Colorado Territory was organized from parts of Kansas, Nebraska, New Mexico, and Utah territories on February 28, 1861, with generally the same boundary as the present state.

Although the territory had not yet been legally established, census data for Colorado are available beginning with the 1860 census. The 1860 population shown for Colorado is for the portion of Kansas Territory that was organized as Colorado Territory. The 1860 population shown for Colorado excludes an undetermined number of people enumerated as part of Nebraska and New Mexico territories. The portion of present-day Colorado in Utah Territory—the portion west of the Rocky Mountains—was not enumerated in 1860. The population of the entire legally established Kansas Territory (of which the enumerated area of Colorado was a part) in 1860 was 141,483.

Data for the legally established state of Colorado are available beginning with the 1880 census.

Colorado Geographical Areas

Counties & County Equivalents

There are 64 counties in Colorado. The cities and counties of Broomfield and Denver are consolidated city-county governments. They are classified as municipal governments, rather than as county governments, because they operate primarily as cities. In each of the remaining 62 counties, the governing body is the board of county commissioners.

County Subdivisions

There are 209 county subdivisions in Colorado. They are all census county divisions (CCDs), which are delineated for statistical purposes, have no legal function, and are not governmental units. CCDs were first established in Colorado for the 1960 census. Prior to 1960, the minor civil divisions used in the census were election precincts.

School Districts

Congressional Districts

For the 111th Congress (January 2009-January 2011), Colorado had seven congressional districts. For the 113th Congress (January 2013-January 2015), Colorado continues to have seven congressional districts as a result of reapportionment based on the 2010 Census. View Map of Colorado Congressional Districts.

State Legislative Districts

There are 35 state senate districts and 65 state house districts in Colorado.